Drafting instrument.



L. B. ANDERSON.

-DRAFTING INSTRUMENT.

APPLIOATION FILED SBP'L 1o, 1913.

Patented May 26, 1914.

Y Zww Andersom LUCIUS B. ANDERSON, OF LOGAN, UTAH, ASSIGNOR TO NOAH B.PRYOR, OF LOGAN,

UTAH.

DRAFTING INSTRUMENT.

Specification of Letters Patent.

Patented May 26, 1914.

Application filed September 10, 1913. Serial No. 789,176.

To all whom it may concern Be it known that I, Lucius B. ANDERSON,

a citizen of the United States, residing at Logan, in the county ofCache and State of Utah, have invented new and useful Improvements inDrafting Instruments, of which the following is a specication.

This invention relates to a drafting instrument for use by engineers,architects, and draftsmen in general.

ln carrying out my invention it is my object to provide a. triangle foruse in laying off angles with an adjustable arm, by which angles of anydesired degree may be determined.

A further object of the invention is to provide a device of thischaracter wherein the body of the triangle is cut away adjacent to oneof its edges and the angularly adjustable arm is pivoted within therecess thus formed and is shaped so that it will t therein to completethe area of the triangle when in its innermost, inoperative position.

A still further object is the provision of readily operable and accuratemeans for determining' the angular adjustment of the movable arm of thedevice, which includes a pointer attached tixedly to the movable arm andwhich is movable through a confining slot within the body of thetriangle, so that the device may be placed upon either of its sidefaces` upon a drawing board andV will lie flat thereon owing to theabsence .of any obstructing projections from the device, it beingunderstood that the flat side faces of the movable arm lie in therespective planes of the side faces of the'triangle body at all times.The slot for the reception of the indica-ting pointer is constructed sothat its extreme walls will serve as means for engagement with thepointer to limit the movement of the movable arm, whereby the said armmay be made to assume either of its extreme positions parallel to theadjacent side edge of the triangle body in a quick and convenientmanner.

The invention consists in the features of construction, combination andarrangement of parts, hereinafter fully described and claimed, referencebeing had to the accompanying drawings, in which:

Figure 1 is a top pla-n view of the device, showing the movable arm inits closed position; F ig. 2 is a similar view showing the arm inextended position, another one of its angularly adjusted positions beingindicated by the dotted lines; and, F ig. 3 is a transverse sectionalview taken on line 3 3 of Fig'. 1.

In the drawing, the numeral 1 designates the body of the triangle whichis constructed of Celluloid or other transparent material in the usualmanner. The said body has one of its base edges cut away as at 2, sothat the longitudinal wall of the recess thus formed is parallel to thesaid edge. A movable arm 8, which latter has its inner end reduced inthickness as at 4 for reception within the sector-shaped slot 5 providedwithin the body l, is pivoted thereto by means of the pivot pin 6 and isadapted, when in its closed position to till the said recess in thetriangle body so as to complete the triangle, the free end of the saidarm being beveled inwardly as at 7 for this purpose. The inner edge 8 ofthe movable arm is graduated to form a linear scale for use in obtaininglongitudinal measurements in connection therewith.

The slot 5 in the body 1 is disposed medially within the said body inspaced relation to its broad side faces and is adapted for the receptionof a pointer 9 which is formed on the reduced inner end portion 4 of themovable arm 3 for movement therewith. The side edges 10 of this pointerare adapted for engagement with the respective side edges 1lV of theslot 5 so as to limit the movement of the arm 3 in either direction,wherein it will be held checked upon arrival into eX- actly parallelrelation to one of the base edges of the triangle body. An arcuate slot12 extends completely through the body 1 in communication with thepointer-confining slo-t 5 and is disposed concentric with respect to thepivot 6 with its outer curved edge 13 engageable with the free end 14 ofthe pointer 9, its edge l5 being disposed inwardly with respect to thepointer extremity. Each side face of the triangle body is graduatedadjacent to the edge 13 of the slot 12 for coperation with the extremity14 of the pointer, and as shown in the drawing', a degree scale 16extends inwardly from one end of the slot and a scale 17 by which thepitch of a roof may be determined is provided adjacent to its other end.The side faces of the body 1 are also graduated adjacent to the inneredge of the slot 12 as indicated at 18 for coperation with alongitudinal, inedially disposed indicator 19 inscribed upon the exposedextremity of the pointer 9 in setting the arm 3 for use in laying olfthe sides of diiferent polygons. Those portions of the side of the bodyI between which the slot 5 is provided may be compressed slightly sothat they will engage the pointer 9 with considerable friction and Willthus serve to secure the latter in its different adjusted positions.

As should be understood readily, the device as a Whole may be laid iatupon a drawing board with either of its side faces in contact therewithand with one of its base edges engaged with a T-square, irrespective ofthe angular position of the arm 3, for use in the various capacities setforth in describing the scale used in connection With the pointer 9.

rIhe capabilities of the device should be clearly apparent to thoseskilled in the arts to which this invention appertains and furtherdescription of the same is unnecessary.

Having thus described my invention, what I claim is:

l. A drafting instrument of the class described comprising a trianglebody, having one of its base edges recessed, an arm pivoted to the bodyand adapted for reception Within said recess to complete the form of thetriangle, the said body being provided with a sector-shaped slot spacedfrom its side faces and communicating with the said recess, and apointer provided upon the arm and adapted to be confined Within the saidslot for movementI therethrough, the body being provided with an arcuatescale for cooperation with the pointer.

2. A drafting instrument of the class described comprising a trianglebody, having one of its edges recessed, an arm pivoted to the body andadapted for reception Within said recess to complete the form of thetriangle, the said body being provided with a sector-shaped slot spacedfrom its side faces and communicating with the said recess and a pointerprovided upon the arm and adapted to be confined Within the said slotfor movement therethrough, the said body being provided with an arcuateslot concentric with the pivot of the said arm and communicating withthe sector-shaped slot for exposing the free end of the pointer and ascale being provided at the outer edge of the arcuate slot forcooperation With the pointer.

3. A drafting instrument of the class described comprising a trianglebody, having one of its base edges recessed, an arm pivoted to the bodyand adapted for reception 'ithin the said recess to complete the form ofthe triangle, the said body being provided With a sector-shaped slotspaced from its side faces and communicating With the said recess, and apointer provided upon the arm and adapted to be confined Within the saidslot for movement therethrough, the said body being provided With anarcuate slot concentric with the pivot of the said arm and communicatingwith the sectorshaped slot for exposing the free end of the pointer, theexposed end of the pointer being provided with a medial longitudinalline and the inner edge of the arcuate slot being provided with a scalefor cooperation there- With.

In testimony whereof I aiiix my signature in presence of two Witnesses.

LUCIUS B. ANDERSON.

Vitnesses 'CHARLES ENGLAND,

Jnssn EARL.

Copies of this patent may be obtained for ve cents each, by addressingthe Commissioner of Patents, Washington, D. C.

